反应详情

A solution of sodium bicarbonate (3.12 g, 0.0371 mol) in water (35 mL) was added to a solution of 4-bromo-2-methoxyaniline (3.00 g, 0.0148 mol) in dioxane (50 mL). The resulting mixture was stirred for 5 minutes and benzyl chloroformate (3.8 g, 0.022 mol) was added dropwise over 3 minutes. The reaction mixture was for two hours, then dioxane was removed under reduced pressure and the water phase was extracted twice with ethyl acetate (100 mL each). The combined organic extracts were dried over magnesium sulfate and after filtration concentrated under reduced pressure. The resulting residue was purified by flash chromatography on silica using ethyl acetate/n-heptane (5:95) as mobile phase to yield benzyl N-(4-bromo-2-methoxyphenyl)carbamate (3.75 g, 0.011 mol) as a white solid: 1H NMR (DMSO-d6, 400 MHz) 8.72 (s, 1H), 7.61 (d, 1H), 7.38 (m, 5H), 7.20 (s, 1H), 7.10 (d, 1H), 5.14 (s, 2H), 3.81 (s, 3H). TLC (ethyl acetate/heptane 1:9) Rf 0.21.

1. waitThe reaction mixture was for two hours
2. customdioxane was removed under reduced pressure
3. extractionthe water phase was extracted twice with ethyl acetate (100 mL each)
4. dry with materialThe combined organic extracts were dried over magnesium sulfate
5. filtrationafter filtration
6. concentrationconcentrated under reduced pressure
7. customThe resulting residue was purified by flash chromatography on silica